Chemistry and process for a stain resistant aqueous house paint free of heavy metals

ABSTRACT

Coating compositions suitable for use as house paints resistant to stains extractable from redwood, cedar and other wood substrates are prepared by a process characterized by the essential stages of (1) emulsifying under alkaline conditions a film-forming oxidatively curable oil or alkyd modified polyurethane, (2) blending therewith a copolymeric or homopolymeric vinyl acetate or acylic latex and (3) incorporating into the mixture aluminum chlorhydrate in the proportion of 1020% by weight of the polyurethane polymer.

United States Patent 11 1 Eekhoff 1 1 CHEMISTRY AND PROCESS FOR A STAIN RESISTANT AQUEOUS HOUSE PAINT FREE OF HEAVY METALS [76] lnventor: Paul S. Eckhoff. PO. Box No. 805.

Melville. L1. N.Y. 11746 [22] Filed: Ju1y23, 1973 [21] Appl. No.1 382.040

[52] US. CL. 260/22 TN; 260/23 TN; 260/292 TN [51] Int. Cl. C09D 3/72; C09D 5/02 158] Field of Search 260/22 TN. 23 TN. 29.2 TN; 117/148 [56] References Cited UNITED STATES PATENTS 3.234.039 2/1966 Lalk et a1 117/148 3.316.200 4/1967 Hatala........ 117/148 3.320.196 5/1967 Rogers........... 117/148 3.369.921 2/1968 Stutz et a1 117/151 1 1 Nov. 11. 1975 3.377.198 4/1968 Sander 117 141':

3.423.346 1/1969 Klauss et a1 2611/22 IN 3.592.580 7/1971 Hoffmann. 117.1151

3.691.117 9/1972 Messerl 11. [4.9 3.756.850 9/1973 Stor} 117/148 3.756.975 9/1973 Story 117,148

Pl'imur E.\uminw'Ronald W. Griffin [57] ABSTRACT Coating compositions suitable for use as house paints resistant to stains extractable from redwood. cedar and other wood substrates are prepared by a process characterized by the essential stages 611 l emulsil ing under alkaline conditions a film-forming oxidatively curable oil or alkyd modified pol xurethane. (21 hlending therewith a copolymeric or homopohmeric \in l acetate or acylic latex and (3) incorporating into the mixture aluminum ch|orh \drate in the proportion of 10-20% by weight of the pol urethane pohmer.

15 Claims. N0 Drawings CHEMISTRY AND PROCESS FOR A STAIN RESISTANT AQUEOUS HOUSE PAINT FREE OF HEAVY METALS EXAMPLES Seven examples follow. Six of these examples have to do with the manufacture of the resin system. The seventh formulation is the paint.

EXAMPLE 1 The first example typifies the production of an intermediate for a high-solids exidatively curable alkydmodified polyurethane resin dissolved in a hydrocarbon solvent. High solids are used for ease and efficiency in manufacture and to hold the quantity of solvent within limits specified in legislation controlling solvent emissions from applied coatings.

Soybean oil 1256 pounds Litharge 9l grams Pentaerythritol, technical grade 146 pounds lhthalic anhydride 2l4 pounds Ethylene glycol 56 pounds Xylol 334 pounds Anti-foam solution k 11.02.

"A common antifoam solution consists of a 2% solution of a silicone resin such as Do'wComing Anti-foam A in a heavy aromatic solvent such as Solvem 150.

to 430F and hold at 430F for approximately 4 hours, 40

at which time the acid number will be approximately 6 to 7. Cool the batch to 300F and add the xylol to reduce the non-volatile content to 84%. Pass the solution through a filter press and pump to a steam-jacketed reactor for the next stage, typified by Example 3, which illustrates the reaction of the alkyd intermediate with toluene diisocyanate.

EXAMPLE 2 This example typifies the production of an intermediate for an oxidatively curable oil-modified polyurethane.

Linseed oil I053 pounds Litharge 2.5 ounces Glycerol l62 pounds Mineral spirits l200 pounds EXAMPLE 3 Example 3 illustrates the conversion of the alkydmodified intermediate of Example 1 into an alkydmodified polyurethane.

Commercially available as Acliv-B Charge intermediate andxylol to a steam-jacketed reactor fitted with a reflux condenser and agitator. Use slow speed agitation (about 40 rpm). Begin heating the mixture of intermediate and xylol while adding the toluene diisocyanate over a period of a half hour. Heat to 200F and maintain the temperature at 200F. Cook to an anticipated viscosity of 120 seconds in a standard 10.65 mm Gardner viscosity vial, which requires about 4 hours. Commence cooling at the anticipated end point and pump in 96.5 pounds of methyl alcohol below the liquid level with the condenser on. Cool to 120F, add the phenanthroline solution and pump the mixture to storage.

The finished product has the following properties:

Body Z3-Z4 Non-volatile content 85% Color (Gardner) 5-7 Acid value of non-volatile resin 5 Pounds per U.S. gallon 8.35

EXAMPLE 4 Example 4 illustrates the conversion of the oil-modified intermediate of Example 2 into an oil-modified Heat the intermediate to 1 10F in a reactor equipped with an agitator. To the stirred intermediate add the toluene diisocyanate at the rate of 0.15 gallons per minute. After 4 gallons have been added, increase the flow rate to 0.4 gallons per minute. When all toluene diisocyanate has been added, hold at 110 for 1 hour, then allow to cool.

The final product has the following properties:

Body Z-Zl Non-volatile content 60.3% Color (Gardner) 6-7 Acid value of non-volatile resin 0.38

EXAMPLE 5 This example illustrates the preparation of a 1000- gallon batch of the alkaline emulsion of polyurethane and latex.

Polyurethane resin at 35% solids. from l335 pounds polymer latex at 55% solids or vinylacrylic latex at 55% solids Heat the polyurethane resin solution to approximately 85F in a high-shear mixing vessel. Add the am monia slowly, with agitation. After the ammonia is well incorporated as indicated by the homogeneity of the mixture, add the lgepal CO-630, then the water. Finally, add the vinyl emulsion gradually and observe the inversion from a water-in-oil" state to the oil-inwater state. if the inversion is properly executed, a small particle size emulsion results, generally below 3 micron average particle size. After inversion, continue agitation for at least minutes. Filter and pump to storage.

The finished emulsion has the following properties:

Viscosity 54-60 Krebs units Non-volatile content 55% Pounds per US. gallon 8.8

EXAMPLE 6 Example 6 illustrates the preparation of the non-filmforming composition containing the tannin precipitant.

Aluminum chlorohydrate, 50% aqueous solu- 140 pounds tion Polyoxyethylated nonylphenol containing 23% ethylene oxide 10 pounds Colloids 677 r 8 pounds Polyethylene glycol P-l200 16 pounds Polyoxycthylated nonylphenol containing 20 pounds 65% ethylene oxide Water l06 pounds Product of Colloids, Inc.

In a vessel equipped with low speed turbine agitation add the materials in the order shown. Pump to storage.

EXAMPLE 7 Using a disc type disperser, add in the order shown:

Water 200 lb Methocel l.5 lb Aluminum chlorohydrate dispersion of Example 6 8|.5 lb. Water dispersible lecithin 6 lb. Ammonia, concentrated 7 lb increase the agitator speed and add the following in the order shown:

Titanium dioxide I44 lb. Alkaline polyurethane-latex emulsion of Example 5 44 lb. Talc or calcium carbonate 125 lb. Zinc oxide 50 lb. l-l i -chlornallyl )-3 ,5 .7-triazal-aronia adamantane chloride 1 lb.

Hold for l() minutes with agitation before adding:

Ethylene glycol Water Potassium tripolyphosphate Polyoxyethylated nonylphenol containing 659 ethylene oxide 2,2.4-trimethylpentand l .3-diol monoisohutyrate Colloids 5818* Reduce agitator speed while adding the following:

Alkaline polyurethane-latex emulsion of Example 5 Product of Colloids, Inc.

45 gallons Non-volatile content 55% Pigment volume concentration 31.8% Pounds per US. gallon l0.95

What i claim is:

l. A composition for the painting or repainting of staining woods, said composition containing an aqueous resin binder formed by blending 1) an aqueous alkaline emulsion of a polyurethane resin based on a drying oil and (2) an aqueous dispersion of a film-forming interpolymer useful as a paint vehicle, said composition being further characterized by the incorporation of aluminum chlorhydrate into said mixed resin binder.

2. The composition of claim 1 wherein the oil-based polyurethane resin comprises 10-20% of the total resinous binder.

3. The composition of claim 2 wherein the oil-based polyurethane is a reaction product of toluene diisocyanate with the alcoholysis product of a drying oil and an polyhydric alcohol.

4. The composition of claim 3 in which the drying oil is selected from the group consisting of linseed, safflower, walnut and soybean oil.

5. The composition of claim 2 wherein the oil-based polyurethane is a reaction product of toluene diisocyanate and a hydroxyl group-containing alkyd resin containing an oxidatively drying oil selected from the group consisting of linseed, safflower, walnut and soybean oils.

6. The composition of claim 1 wherein the film-forming interpolymer is a homopolymen'c or copolymeric vinyl acetate latex.

7. The composition of claim 6 wherein the film-forming interpolymer is the copolymer of vinyl acetate with one or more copolymerizable monomers chosen from the group consisting of butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, dibutyl maleate, di-isobutyl maleate, di-Z-ethylhexyl maleate, dibutyl fumarate, diisobutyl fumarate, di-Z-ethylhexyl fumarate, vinyl ester of versatic acid, and ethylene.

8. The composition of claim 1 wherein the film-forming interpolymer is a l00%-acrylic latex.

9. The composition of claim 1 wherein the polyurethane resin is dissolved in a maximum of 25% its weight of hydrocarbon solvent.

10. The composition of claim 9 wherein the hydrocarbon solvent is selected from the group consisting of xylene and mineral spirits.

11. A composition of claim 9 wherein the aluminum chlorohydrate is incorporated as a composition formed 15. The process of preparing a bleed resistant paint containing the essential steps of l) blending an alkaline emulsion of a polyurethane resin or solution thereof in a hydrocarbon solvent with an aqueous dispersion of a filogenic interpolymer suitable as a paint vehicle and (2) incorporating into said blend a composition containing aluminum chlorhydrate in an amount up to 10% of total vehicle solids, surface active agents and defoamers dispersed in a medium consisting of ethylene glycol or propylene glycol. 

1. A COMPOSITION FOR THE PAINTING OR REPAINTING OF STAINING WOODS, SAID COMPOSITION CONTAINING AN AQUEOUS RESIN BINDER FORMED BY BLENDING (1) AN AQUEOUS ALKALINE EMULSION OF A POLYURETHANE RESIN BASED ON A DRYING OIL AND (2) AN AQUEOUS DISPERSION OF A FILM-FORMING INTERPOLYMER USEFUL AS A PAINT VEHICLE, SAID COMPOSITION BEING FURTHER CHARACTERIZED BY THE INCORPORATION OF ALUMINUM CHLORHYDRATE INTO SAID MIXED RESIN BINDER.
 2. The composition of claim 1 wherein the oil-based polyurethane resin comprises 10-20% of the total resinous binder.
 3. The composition of claim 2 wherein the oil-based polyurethane is a reaction product of toluene diisocyanate with the alcoholysis product of a drying oil and an polyhydric alcohol.
 4. The composition of claim 3 in which the drying oil is selected from the group consisting of linseed, safflower, walnut and soybean oil.
 5. The composition of claim 2 wherein the oil-based polyurethane is a reaction product of toluene diisocyanate and a hydroxyl group-containing alkyd resin containing an oxidatively drying oil selected from the group consisting of linseed, safflower, walnut and soybean oils.
 6. The composition of claim 1 wherein the film-forming interpolymer is a homopolymeric or copolymeric vinyl acetate latex.
 7. The composition of claim 6 wherein the film-forming interpolymer is the copolymer of vinyl acetate with one or more copolymerizable monomers chosen from the group consisting of butyl acrylate, isobutyl acrylate, 2-ethylhexyl acrylate, dibutyl maleate, di-isobutyl maleate, di-2-ethylhexyl maleate, dibutyl fumarate, diisobutyl fumarate, di-2-ethylhexyl fumarate, vinyl ester of versatic acid, and ethylene.
 8. The composition of claim 1 wherein the film-forming interpolymer is a 100%-acrylic latex.
 9. The composition of claim 1 wherein the polyurethane resin is dissolved in a maximum of 25% its weight of hydrocarbon solvent.
 10. The composition of claim 9 wherein the hydrocarbon solvent is selected from the group consisting of xylene and mineral spirits.
 11. A composition of claim 9 wherein the aluminum chlorohydrate is incorporated as a composition formed by blending with surface active agents, a glycol and a defoaming agent.
 12. The composition of claim 1 wherein the aluminum chlorohydrate comprises 8-10% of the total vehicle solids.
 13. A composition of claim 1 in which the pH of the finished paint is maintained between 9.5 and 10.5.
 14. A composition for painting wood surfaces containing an aluminum chlorhydrate compound, in an amount up to 10% of the total vehicle solids, and an alkaline emulsion of a polyurethane resin or solution of a polyurethane resin.
 15. The process of preparing a bleed resistant paint containing the essential steps of (1) blending an alkaline emulsion of a polyurethane resin or solution thereof in a hydrocarbon solvent with an aqueous dispersion of a filogenic interpolymer suitable as a paint vehicle and (2) incorporating into said blend a composition containing aluminum chlorhydrate in an amount up to 10% of total vehicle solids, surface active agents and defoamers dispersed in a medium consisting of ethylene glycol or propylene glycol. 